Macrostomus longipennis, Rafael & Cumming, 2009

Rafael, José Albertino & Cumming, Jeffrey M., 2009, Revision of the genus Macrostomus Wiedemann (Diptera: Empididae: Empidinae). I. The ferrugineus species-group, Zootaxa 2064 (1), pp. 39-56 : 46-48

Macrostomus longipennis , n. sp.

( Figs. 4a–i , 9 )

Diagnosis. Thorax, abdomen and legs predominantly yellow; postcranium black dorsally, yellowish ventrally; male tergite 8 with distal projection truncated. Female without pinnate scales on hind tibia; wing entirely brown infuscated.

Description. Holotype male. Frons approximately one third anterior ocellus width. Face slightly wider than frons only at ventral margin. Postcranium black dorsally, yellow ventrally. Antenna with scape and pedicel yellowish. Palpus yellow. Thorax shining yellow with yellow to gray-brown pruinescence. Setae: 4 dorsocentrals; 1 supra-alar presutural; 2 pairs of scutellars (rarely one pair); 3–5 antepronotals; 2–3 tiny proepisternals; 2–5 katatergitals. Legs shining, yellow with apex of mid and hind femora, apex of hind tibia and all tarsi black, except fore and mid first tarsomeres yellow and hind first tarsomere slightly yellow on basal third. Mid tibia with one dorsal seta slightly stout at basal fifth; hind tibia with 4–5 slender but rather short dorsal setae; first hind tarsomere with two longer dorsal setae. Wing distinctly brown infuscated at costal and apical margin ( Fig. 4a ); M 1 and M 2 veins distinct apically, not evanescent. Halter dark brown to black. Abdomen shining yellow to orange, sometimes black because of internal structures. Terminalia black dorsally, yellow ventrally. Tergite 8 ( Fig. 4b ) with blunt truncated distal projection. Sternite 8 with small protuberance posterodorsally ( Fig. 4c ). Epandrium with anterodorsal and posterodorsal protuberances of subequal length ( Fig. 4c ). Anterior cercus very elongate and bifid distally; posterior cercus ( Fig. 4d ) somewhat rounded, with many slender anterodorsal setae and simple incurved protuberance at margin. Hypandrium ( Fig. 4e ) with many setae medially, small row of spine-like subapical setae and distal anterior margin developed over shortened paired protuberances.

Size. Body length 5.9 mm; wing length 6.7 mm.

Female. Frons as wide as anterior ocellus width; face narrower than frons, approximately one third anterior ocellus width. Mid tibia with no stout setae. Hind tibia without pinnate scales. Wing ( Fig. 4f ) wider than in male, entirely brown infuscated with cell dm, CuA 2 and anal margin lighter; posterior margin sinuose. Abdomen somewhat yellow reddish with terminalia black, sparsely gray pruinose. Terminalia with tergite 8 and sternite 8 very elongated ( Figs. 4g –h ). Genital fork ( Fig. 4i ) predominantly membranous with small sclerotized rod and two slightly sclerotized spots.

Size. Body length 6.0 mm; wing length 6.6 mm.

Geographical records. Brazil (Amazonas state), Fig. 9 .

Material. Holotype ♂: BRASIL, Am [azonas], Pq [Parque] N[acional] [do] Jau , Rio Unini, Democracia, 014354S–615432W, 20–24.vi.1996 // A.L. Henriques, J.[F.] Vidal & F.L. Oliveira ( INPA).

Paratypes: same data as holotype (1♀ INPA) ; Igarapé Miratucu, 015702S–614901W, 23–28.vii.1995, varredura, J.A. Rafael & J.F. Vidal (1♂ 2♀ CNC) ; Tabatinga, 13–17.i.1992, J.Vidal & Lilian, arm. Malaise (3♂ 1♀ INPA) .

Holotype condition. Good, not dissected.

Etymology. From Latin longi = elongated, penna = wing, in reference to the elongate wing.

Discussion. Macrostomus longipennis , n. sp. appears close to M. occidentalis Rafael & Cumming on the basis of the similar shaped tergite 8 and the yellow postcranium ventrally. It differs from M. occidentalis and other species by the very elongate distally bifid anterior cercus and by the somewhat rounded posterior cercus that bears a simple incurved protuberance at its margin and many slender anterodorsal setae.

Figures

FIGURE 4. Macrostomus longipennis, n. sp., paratypes. A–E, male; A, wing; B, tergite 8, dorsal view with right setae omitted; C, terminalia, lateral view; D, detail of posterior cercus; E, hypandrium and phallus, lateral view. F–I, female; F, wing; G, tergite and sternite 8, lateral view; H, tergite 8, dorsal view; I, genital fork. Scales: B,C,E,G,H = 0.2 mm; D,I = 0.1 mm.

FIGURE 9. Distribution map of species belonging to the Macrostomus ferrugineus species-group with tergite 8 truncated or forked distally. Symbols represent the known collection localities as follows: diamond = M. longipennis, n. sp.; open circle = M. furcatus, n. sp.; open triangle = M. flavus, n. sp.; square = M. fulvithorax; star = M. occidentalis.